Embodiments of the inventive concept relate to methods of operating a universal flash storage (UFS) device, and more particularly, to methods of operating a UFS device capable of triggering a warm reset of a link. Embodiments of the inventive concept also relate to methods of operating a UFS host and methods of operating a UFS system including a UFS device and a UFS host.
A UFS host and UFS device send and/or receive (hereafter, “communicate”) data with each other via a link. The combination of UFS device, UFS host and connecting link may be termed a UFS system. Within a UFS system, a link may be variously established between the UFS device and UFS host using one or more signal(s) communication technologies (e.g., hardwired, wireless, radio frequency (RF), infrared (IR), etc.).
Circumstances routinely arise wherein communication between a UFS host and UFS device via an established link fails. For example, assuming that a UFS write command is being processed by the UFS device when a link failure occurs, the UFS device will be unable to transmit a corresponding write command completion response (i.e., a message indicating successful completion of the write command) to the UFS host. In response to the failure to receive a write command completion response, a UFS driver in the UFS host will wait for a predetermined time-out period. Following expiration of the time-out period, the UFS host determines that a time-out error has occurred. Thereafter, the UFS driver may transmit a write command fail indication to (e.g.) an application indicating that execution of the write command has failed. As a result, some corrective action is usually necessary and may be taken by the application, the UFS driver, or elsewhere in the UFS system. Until such corrective action is taken, the UFS system cannot operate normally even with restoration of the link.